Fast forward to 2050
The year is 2050. Yankele arrives at the gates. He tugs up at the navy blue sleeve of his school sweater, and flashes an armband at the metallic sign attached to the brick wall. A cryptographic protocol is deployed, Yankele and the school authenticate themselves, each verifies that the other is kosher, and that the kashrut certification was not revoked, or "cheremed", as the elders call it. The gates slide open, and Yankele is allowed into the hallowed sanctuaries of the Yeshiva day school. (The elders are rather proud of their two way authentication scheme. Before it was only possible to make sure the student is kosher, but what would happen if the school would rise in revolt, and overstep the proper boundaries? Now it's possible by one simple command to have the school shut down) Inside the building Yankele stops to greet friends, both first checking that the other is kosher according to their families minhagim. Parents can program in permitted kosher associates for the...